Cairo: A Vector Graphics Library: PostScript Surfaces

## PostScript Surfaces PostScript Surfaces — Rendering PostScript documents |

## Functions

cairo_surface_t * | cairo_ps_surface_create ()
cairo_surface_t * | cairo_ps_surface_create_for_stream ()
void | cairo_ps_surface_restrict_to_level ()
void | cairo_ps_get_levels ()
const char * | cairo_ps_level_to_string ()
void | cairo_ps_surface_set_eps ()
cairo_bool_t | cairo_ps_surface_get_eps ()
void | cairo_ps_surface_set_size ()
void | cairo_ps_surface_dsc_begin_setup ()
void | cairo_ps_surface_dsc_begin_page_setup ()
void | cairo_ps_surface_dsc_comment ()

## Types and Values

#define | CAIRO_HAS_PS_SURFACE
enum | cairo_ps_level_t

## Object Hierarchy

## Description

The PostScript surface is used to render cairo graphics to Adobe PostScript files and is a multi-page vector surface backend.

## Functions

### cairo_ps_surface_create ()

    cairo_surface_t *
    cairo_ps_surface_create (const char *filename,
                             double width_in_points,
                             double height_in_points);

Creates a PostScript surface of the specified size in points to be written to `filename` . See `cairo_ps_surface_create_for_stream()` for a more flexible mechanism for handling the PostScript output than simply writing it to a named file.

Note that the size of individual pages of the PostScript output can vary. See `cairo_ps_surface_set_size()`.

#### Parameters

filename | a filename for the PS output (must be writable), `NULL` may be used to specify no output. This will generate a PS surface that may be queried and used as a source, without generating a temporary file. |
width_in_points | width of the surface, in points (1 point == 1/72.0 inch) |
height_in_points | height of the surface, in points (1 point == 1/72.0 inch) |

#### Returns

a pointer to the newly created surface. The caller owns the surface and should call `cairo_surface_destroy()` when done with it.

This function always returns a valid pointer, but it will return a pointer to a "nil" surface if an error such as out of memory occurs. You can use `cairo_surface_status()` to check for this.

Since 1.2

### cairo_ps_surface_create_for_stream ()

    cairo_surface_t *
    cairo_ps_surface_create_for_stream (cairo_write_func_t write_func,
                                        void *closure,
                                        double width_in_points,
                                        double height_in_points);

Creates a PostScript surface of the specified size in points to be written incrementally to the stream represented by `write_func` and `closure` . See `cairo_ps_surface_create()` for a more convenient way to simply direct the PostScript output to a named file.

Note that the size of individual pages of the PostScript output can vary. See `cairo_ps_surface_set_size()`.

#### Parameters

write_func | a cairo_write_func_t to accept the output data, may be `NULL` to indicate a no-op `write_func` . With a no-op `write_func` , the surface may be queried or used as a source without generating any temporary files. |
closure | the closure argument for `write_func` |
width_in_points | width of the surface, in points (1 point == 1/72.0 inch) |
height_in_points | height of the surface, in points (1 point == 1/72.0 inch) |

#### Returns

a pointer to the newly created surface. The caller owns the surface and should call `cairo_surface_destroy()` when done with it.

This function always returns a valid pointer, but it will return a pointer to a "nil" surface if an error such as out of memory occurs. You can use `cairo_surface_status()` to check for this.

Since 1.2

### cairo_ps_surface_restrict_to_level ()

    void
    cairo_ps_surface_restrict_to_level (cairo_surface_t *surface,
                                        cairo_ps_level_t level);

Restricts the generated PostSript file to `level` . See `cairo_ps_get_levels()` for a list of available level values that can be used here.

This function should only be called before any drawing operations have been performed on the given surface. The simplest way to do this is to call this function immediately after creating the surface.

#### Parameters

surface | a PostScript cairo_surface_t |
level | PostScript level |

Since 1.6

### cairo_ps_get_levels ()

    void
    cairo_ps_get_levels (cairo_ps_level_t const **levels,
                         int *num_levels);

Used to retrieve the list of supported levels. See `cairo_ps_surface_restrict_to_level()`.

#### Parameters

levels | supported level list |
num_levels | list length |

Since 1.6

### cairo_ps_level_to_string ()

    const char *
    cairo_ps_level_to_string (cairo_ps_level_t level);

Get the string representation of the given `level` id. This function will return `NULL` if `level` id isn't valid. See `cairo_ps_get_levels()` for a way to get the list of valid level ids.

#### Parameters

level | a level id |

#### Returns

the string associated to given level.

Since 1.6

### cairo_ps_surface_set_eps ()

    void
    cairo_ps_surface_set_eps (cairo_surface_t *surface,
                              cairo_bool_t eps);

If `eps` is `TRUE`, the PostScript surface will output Encapsulated PostScript.

This function should only be called before any drawing operations have been performed on the current page. The simplest way to do this is to call this function immediately after creating the surface. An Encapsulated PostScript file should never contain more than one page.

#### Parameters

surface | a PostScript cairo_surface_t |
eps | `TRUE` to output EPS format PostScript |

Since 1.6

### cairo_ps_surface_get_eps ()

    cairo_bool_t
    cairo_ps_surface_get_eps (cairo_surface_t *surface);

Check whether the PostScript surface will output Encapsulated PostScript.

#### Parameters

surface | a PostScript cairo_surface_t |

#### Returns

`TRUE` if the surface will output Encapsulated PostScript.

Since 1.6

### cairo_ps_surface_set_size ()

    void
    cairo_ps_surface_set_size (cairo_surface_t *surface,
                               double width_in_points,
                               double height_in_points);

Changes the size of a PostScript surface for the current (and subsequent) pages.

This function should only be called before any drawing operations have been performed on the current page. The simplest way to do this is to call this function immediately after creating the surface or immediately after completing a page with either `cairo_show_page()` or `cairo_copy_page()`.

#### Parameters

surface | a PostScript cairo_surface_t |
width_in_points | new surface width, in points (1 point == 1/72.0 inch) |
height_in_points | new surface height, in points (1 point == 1/72.0 inch) |

Since 1.2

### cairo_ps_surface_dsc_begin_setup ()

    void
    cairo_ps_surface_dsc_begin_setup (cairo_surface_t *surface);

This function indicates that subsequent calls to `cairo_ps_surface_dsc_comment()` should direct comments to the Setup section of the PostScript output.

This function should be called at most once per surface, and must be called before any call to `cairo_ps_surface_dsc_begin_page_setup()` and before any drawing is performed to the surface.

See `cairo_ps_surface_dsc_comment()` for more details.

#### Parameters

surface | a PostScript cairo_surface_t |

Since 1.2

### cairo_ps_surface_dsc_begin_page_setup ()

    void
    cairo_ps_surface_dsc_begin_page_setup (cairo_surface_t *surface);

This function indicates that subsequent calls to `cairo_ps_surface_dsc_comment()` should direct comments to the PageSetup section of the PostScript output.

This function call is only needed for the first page of a surface. It should be called after any call to `cairo_ps_surface_dsc_begin_setup()` and before any drawing is performed to the surface.

See `cairo_ps_surface_dsc_comment()` for more details.

#### Parameters

surface | a PostScript cairo_surface_t |

Since 1.2

### cairo_ps_surface_dsc_comment ()

    void
    cairo_ps_surface_dsc_comment (cairo_surface_t *surface,
                                  const char *comment);

Emit a comment into the PostScript output for the given surface.

The comment is expected to conform to the PostScript Language Document Structuring Conventions (DSC). Please see that manual for details on the available comments and their meanings. In particular, the %%IncludeFeature comment allows a device-independent means of controlling printer device features. So the PostScript Printer Description Files Specification will also be a useful reference.

The comment string must begin with a percent character (%) and the total length of the string (including any initial percent characters) must not exceed 255 characters. Violating either of these conditions will place `surface` into an error state. But beyond these two conditions, this function will not enforce conformance of the comment with any particular specification.

The comment string should not have a trailing newline.

The DSC specifies different sections in which particular comments can appear. This function provides for comments to be emitted within three sections: the header, the Setup section, and the PageSetup section. Comments appearing in the first two sections apply to the entire document while comments in the BeginPageSetup section apply only to a single page.

For comments to appear in the header section, this function should be called after the surface is created, but before a call to `cairo_ps_surface_dsc_begin_setup()`.

For comments to appear in the Setup section, this function should be called after a call to `cairo_ps_surface_dsc_begin_setup()` but before a call to `cairo_ps_surface_dsc_begin_page_setup()`.

For comments to appear in the PageSetup section, this function should be called after a call to `cairo_ps_surface_dsc_begin_page_setup()`.

Note that it is only necessary to call `cairo_ps_surface_dsc_begin_page_setup()` for the first page of any surface. After a call to `cairo_show_page()` or `cairo_copy_page()` comments are unambiguously directed to the PageSetup section of the current page. But it doesn't hurt to call this function at the beginning of every page as that consistency may make the calling code simpler.

As a final note, cairo automatically generates several comments on its own. As such, applications must not manually generate any of the following comments:

Header section: %!PS-Adobe-3.0, %%Creator, %%CreationDate, %%Pages, %%BoundingBox, %%DocumentData, %%LanguageLevel, %%EndComments.

Setup section: %%BeginSetup, %%EndSetup

PageSetup section: %%BeginPageSetup, %%PageBoundingBox, %%EndPageSetup.

Other sections: %%BeginProlog, %%EndProlog, %%Page, %%Trailer, %%EOF

Here is an example sequence showing how this function might be used:

    cairo_surface_t *surface = cairo_ps_surface_create (filename, width, height);
    ...
    cairo_ps_surface_dsc_comment (surface, "%%Title: My excellent document");
    cairo_ps_surface_dsc_comment (surface, "%%Copyright: Copyright (C) 2006 Cairo Lover")
    ...
    cairo_ps_surface_dsc_begin_setup (surface);
    cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *MediaColor White");
    ...
    cairo_ps_surface_dsc_begin_page_setup (surface);
    cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *PageSize A3");
    cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *InputSlot LargeCapacity");
    cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *MediaType Glossy");
    cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *MediaColor Blue");
    ... draw to first page here ..
    cairo_show_page (cr);
    ...
    cairo_ps_surface_dsc_comment (surface, "%%IncludeFeature: *PageSize A5");
    ...

#### Parameters

surface | a PostScript cairo_surface_t |
comment | a comment string to be emitted into the PostScript output |

Since 1.2

## Types and Values

### CAIRO_HAS_PS_SURFACE

    #define CAIRO_HAS_PS_SURFACE 1

Defined if the PostScript surface backend is available. This macro can be used to conditionally compile backend-specific code.

Since 1.2

### enum cairo_ps_level_t

cairo_ps_level_t is used to describe the language level of the PostScript Language Reference that a generated PostScript file will conform to.

#### Members

CAIRO_PS_LEVEL_2 | The language level 2 of the PostScript specification. (Since 1.6) |
CAIRO_PS_LEVEL_3 | The language level 3 of the PostScript specification. (Since 1.6) |

Since 1.6

## See Also

cairo_surface_t